Retro meets Modern: Astell&Kern's new Luxury Tube-Toting Digital Player

SP4000T & Clarus debut at next week’s High End Show Vienna – booth HX4, M04

NEWS EMBARGOED UNTIL 3AM BST, FRIDAY 29 MAY

Astell&Kern, a global leader in portable high-resolution audio players and accessories, has announced an expansion of the A&ultima flagship player line with the launch of the SP4000T and Clarus, a new In-Ear Monitor.  Both products will make their global debut at the High End Show, 4–7 June at booth HX4, M04, Austria Center Vienna. 

• SP4000T: The industry’s first digital audio player to feature RAYTHEON JAN6418 MIL-Spec vintage vacuum tubes in a Quad configuration
• SP4000T: Triple Tube Mode with up to 54 sound combinations - a true Analogue Sound Palette
• SP4000T: Astell&Kern’s first dual Wi-Fi antenna design, delivering significantly faster and more stable wireless streaming and downloads
• Clarus: A new nine-driver Tribrid IEM (using dynamic, balanced armature and MEMS drivers) crafted from premium-grade aluminium.
• Clarus: Each of the nine drivers dedicated exclusively to its own frequency range.

Retro meets modern

The A&ultima SP4000T combines the best of cutting-edge digital audio with classic analogue technology. It is the industry's first DAP to feature the RAYTHEON JAN6418 MIL-Spec vintage vacuum tube in a Quad configuration.

With independent dual-tube structures dedicated to the left and right channels respectively, the channel-separated design, once exclusive to home audio high-end tube amplifiers, has finally been brought to the world of DAPs.

Each of the four tubes is precisely measured for its noise and gain characteristics before being paired, then fully isolated from noise through independent modular flexible PCBs and a multi-layered architecture, a design that only Astell&Kern, with its long experience in analogue circuits and vacuum tubes, could bring to life.

Triple Tube Mode in the SP4000T is a DAP-industry first Combined with the T Series Signature Triple AMP Mode and the Tube Current level adjustment, it offers up to 54 possible combinations tailored to any genre or preference, a true Analogue Sound Palette.

The Astell&Kern SP4000T offers three distinct tube sound modes, each delivering its own unique sonic character. Triode Mode emphasises rich harmonics and lush, lingering warmth, creating an emotional and immersive presentation ideal for vocals and acoustic instruments. Ultra Linear Mode balances the tonal richness of Triode with the power and control of Pentode, producing a refined yet authoritative sound suited to a wide range of music genres. Pentode Mode focuses on maximum output and dynamic impact, preserving tube warmth whilst delivering a cleaner, more direct, and energetic presentation.

Combining Astell&Kern’s exclusive TERATON ALPHA technology with Quad-configured Real Vacuum Tubes and advanced OPAMP design, the SP4000T delivers both authentic analogue warmth and ultra-high-resolution clarity. Users can choose between dedicated OP AMP Mode for powerful dynamics, expansive detail, and low-noise precision, or TUBE AMP Mode for the rich, emotional character and natural soundstage unique to true vacuum tube audio.

An advanced 5-stage HYBRID AMP Mode that blends the strengths of both amps, allowing listeners to fine-tune the balance between analogue warmth and high-resolution transparency to match their personal listening preferences.

The SP4000T introduces an upgraded 5-stage second-generation Anti-Microphonic Architecture (up from the previous 4-stage design) to suppress microphonic noise (noise generated in vacuum tubes from even the most minor external vibrations).

Cutting-edge digital spec – including faster audio streaming

The Astell&Kern SP4000T is designed for modern streaming-focused listening, running Android 15 with full Google Play Store support whilst maintaining Astell&Kern’s flagship analogue sound quality. Its proprietary ADP (Astell&Kern Direct Path) technology bypasses Android’s standard sample rate conversion limitations to enable true lossless, bit-perfect playback from streaming services. The SP4000T also introduces Astell&Kern’s first dual Wi-Fi antenna design, delivering significantly faster and more stable wireless streaming and downloads, with internal testing showing up to twice the 5GHz download speed of previous models.

The Astell&Kern SP4000T combines Astell&Kern’s most advanced audio technologies to deliver a deeper, more refined analogue sound experience. Its fully discrete circuit architecture separates digital and analogue signal processing using dual flagship AK4499EX DACs and dedicated AK4191EQ processors for each channel, reducing noise and enhancing clarity, depth, and purity across the entire signal path.

Building on the SP4000 platform, the SP4000T also incorporates High Driving Mode with parallel OPAMP configuration for greater dynamic range and more detailed, immersive sound reproduction. Proprietary ESA (Enhanced Signal Alignment) technology minimises group delay and frequency distortion, whilst Advanced DAR technology restores lost harmonics before applying upsampling for more natural, lifelike playback.

Additional refinements including Any Layer HDI PCB technology and a 99.9% pure copper Shield Can further minimise signal loss, noise, and electromagnetic interference, resulting in exceptionally clean, vivid, and highly resolved audio performance.

The SP4000T is packaged with a premium leather “Cognac’ coloured case crafted using 'MINERVA' leather from 'BADALASSI CARLO', a renowned leather workshop located in the San Miniato district of Florence, Italy.

The Astell&Kern SP4000T combines flagship-level connectivity and high-resolution playback capabilities with advanced wireless and user-focused features. It offers 256GB of internal storage with microSD expansion up to 1.5TB, supports native playback up to 32-bit/768kHz PCM and DSD512, and features a 6-inch Full HD touchscreen alongside dual-band Wi-Fi, DLNA networking, USB audio output, and USB DAC functionality for Mac and Windows PCs. 

Wireless performance is enhanced through support for aptX Adaptive and LDAC codecs, whilst BT Sink mode allows the SP4000T to function as a high-quality Bluetooth DAC for external devices such as smartphones. Features like ReplayGain, AK File Drop wireless transfers, USB PD 3.0 fast charging, and customisable battery protection further improve everyday usability.

For extended listening comfort, the SP4000T also includes advanced Crossfeed controls that recreate a more speaker-like listening experience through headphones, allowing users to fine-tune spatial presentation and reduce listening fatigue over long sessions.

Pricing and availability for the SP4000T in Stainless Steel and Copper will be announced shortly. 

Two additional premium leather cases will be available for the SP4000T. A black colour case, crafted from soft cowhide by GRUPPO MASTROTTO, delivers an exceptionally soft touch, with a uniform surface quality and a distinctively vibrant Italian colouration. An olive-coloured case, crafted from premium vegetable-tanned leather by BADALASSI CARLO, is crafted through a proprietary tanning and dyeing process.  Both cases feature a standing mechanism on the back to provide greater convenience in use.

Clarus In-Ear Monitor 

Clarus is the fourth model in Astell&Kern's IEM series, defined by an unwavering pursuit of sound faithful to the original. Delivering music exactly as the artist intended — transparent and free from distortion. It is a philosophy the brand has consistently upheld, and one that Clarus carries forward.

Constructed of 6061-T6 Aluminium, Clarus is designed around a nine-driver Tribrid architecture, allowing each driver to perform at its best within its dedicated range. A dynamic driver delivers the natural weight and depth of the low frequencies, a precisely arranged array of Balanced Armature (BA) drivers reproduces the detail and resolution of the mids and highs, and the latest MEMS drivers render even the most delicate upper frequencies with exceptional precision.

True to its name, Clarus is an answer to clarity. From the deepest bass to the most subtle highs, it reveals the natural detail and sense of space that lives within the music itself.

Clarus will be available for demo in the Astell&Kern booth at High End Vienna 2026. Pricing, availability and further details will be confirmed in due course.